Ex not continuing toilet traing

[Magicpaint]

My DD is now using the big toilet. However when she goes to her father's for the weekend he puts pull ups or a nappy on her. She's three and a half and is doing well. I've asked him time and time again, provided her toilet seat, plenty of clean clothes and clean knickers, but they come back not worn and she is returned to me in a pull up/nappy. This puts her back so much but he just won't listen. What do I do?

Wow this is awful! What's your relationship like? I'm sure you have but I would think that explaining how important consistency is to her development and his actions may be confusing her
Have you asked him why he isn't willing to help her progression?
Also maybe tell him that you need to nail this before school starts in sept x

Good luck. I done all potty training but my ex followed my lead when DS went EOW x

Is it worth saying to your dd that (without making it a big deal about dad vs you) nappies are what she does at daddy's but everywhere else she uses the toilet/potty? Before she goes and then when she comes home first thing you take nappy off and reinforce nappies are for ar daddy's house but everywhere else is toilet? Sort of the approach to uncooperative daycare in oh crap?
Obviously work on ex too. Kids know that you can do different things different places.